EERE Success Story—Open-Source Testing Reaches New Milestone for Wave Energy

April 8, 2016

You are here

WEC-Sim Phase 1 testing at the Oregon State University Hinsdale Directional Wave Basin.

WEC-Sim Phase 1 testing at the Oregon State University Hinsdale Directional Wave Basin.

Ocean wave energy is a developing next-generation technology. Wave energy converters are important for renewable energy development because the wave energy resource in the United States is substantial, and co-located with a large percentage of the population.

Sandia National Laboratories successfully led and completed Phase 1 of wave tank testing in the Hinsdale Directional Wave Basin of the Floating Oscillating Surge Wave Energy Converter (FOSWEC). Successful completion of Phase 1 testing is a huge milestone because it required the cooperation of a large team of people across the country to design and construct a novel wave energy converter -- with state-of-the-art instrumentation--characterize the FOSWEC’s mass properties, and run system identification tests in the wave basin. Results from Phase 1 testing are being used to validate the Wave Energy Converter (WEC)-Sim numerical code, and findings from these tests are being used to iterate and improve the device for Phase 2.

Device performance for wave energy converters relies heavily on numerical modeling. Numerical models are used for design optimization, a very important phase in the design process because understanding a WEC’s dynamics and power performance is critical to achieving successful open-ocean deployments. Sandia National Laboratories and the National Renewable Energy Laboratory jointly developed and released the open-source numerical code Wave Energy Converter SIMulator (WEC-Sim) in summer 2013.

WEC-Sim is a numerical code developed specifically to model the multi-body dynamics and power performance of wave energy converters when subject to operational and extreme waves. In order for any code to be successful, it must go through verification and validation. The WEC-Sim code has been compared extensively to other codes, but was missing the critical piece of validation by comparing with experimental data. The numerical/experimental comparison is currently underway. The team is also working on conference papers on this topic, which will validate the WEC-Sim code. Experimental validation of the WEC-Sim code is the primary objective of WEC-Sim wave tank testing. Code validation is a critical part of any code development project. It serves as a way to prove the validity of the numerical solution, and instill confidence in its user-base to the accuracy of the numerical solution. Additionally, results of the experimental test campaign will be released as an open-access device design and data set that can be used as a numerical benchmarking case for the WEC-Sim code.

Most experimental testing is performed by wave energy companies themselves, therefore the data is proprietary and not released publicly. There are now a few other examples of open-source data sets, but this is new, and nothing of the WEC-Sim testing’s complexity has been released. This will serve as a numerical benchmarking case for many codes in the future, not just WEC-Sim.

EERE directly funded Sandia National Laboratories and the National Renewable Energy Laboratory for the WEC-Sim code development and wave tank testing at $4.5 million over the course of four years. $4.5 million is the total project cost over the four years, and was split evenly between both labs.